Mobile telephony standards converter

1. Testing apparatus for testing a mobile telephone of a first type which transmits, at any one time, on one transmit frequency of a first set of transmit frequencies and which receives, at any one time, on one receive frequency of a first set of receive frequencies, said testing apparatus comprising: a base station simulator for testing mobile telephones of a second type each of which transmits, at any one time, on a respective one transmit frequency of a second set of transmit frequencies and which receives, at any one time, on a respective one receive frequency of a second set of receive frequencies; and an adapter comprising: a first interface which receives from said mobile telephone of said first type a signal at said one transmit frequency of said first set of transmit frequencies and which transmits to said mobile telephone of said first type a signal at said one receive frequency of said first set of receive frequencies, a second interface which receives from said base station simulator a signal at said one receive frequency of said second set of receive frequencies and which transmits to said base station simulator a signal at said one transmit frequency of said second set of transmit frequencies, a first propagation path which propagates said signal at said one transmit frequency of said first set of transmit frequencies from said first interface to said second interface, a second propagation path which propagates said signal at said one receive frequency of said second set of receive frequencies from said second interface to said first interface, a first frequency converter along said first propagation path which converts said one transmit frequency of said first set of transmit frequencies to a corresponding frequency of said second set of transmit frequencies, and a second frequency converter along said second propagation path which converts said one receive frequency of said second set of receive frequencies to a corresponding frequency of said first set of receive frequencies.

2. The testing apparatus of claim 1 wherein said first and second frequency converters comprise, respectively, a first mixer and a first local oscillator, and a second mixer and a second local oscillator.

3. The testing apparatus of claim 2 wherein each of said first and second local oscillators comprises a respective voltage controlled oscillator and a respective phase-lock loop circuit.

4. The testing apparatus of claim 3 wherein said phase-lock loop circuit of said first oscillator and said phase-lock loop circuit of said second oscillator are included in one dual phase-lock loop device.

5. The testing apparatus of claim 4 wherein said dual phase-lock loop device comprises a control input for selecting frequencies of said first and second oscillators.

6. The testing apparatus of claim 3 wherein each said phase-lock loop circuit comprises a respective control input for selecting a respective frequency of said first and second oscillators.

7. The testing apparatus of claim 1 wherein: said mobile telephone is a PCS telephone; said base station simulator is a cellular base station simulator for testing cellular telephones; said first set of transmit frequencies ranges from about 1850.01 MHz to about 1909.95 MHz; said first set of receive frequencies ranges from about 1930.05 MHz to about 1989.99 MHz; said second set of transmit frequencies ranges from about 824.01 MHz to about 848.97 MHz; and said first set of receive frequencies ranges from about 869.01 MHz to about 893.97 MHz.